Synthesis, characterization and magnetic properties of Mg2+ doped green pigment Cobalt aluminate nanoparticles

The green pigment cobalt aluminate nanoparticles have been prepared by the simple and cost-effective co-precipitation method. And also, the structural, optical and magnetic properties of cobalt aluminate nanoparticles are altered by Mg2+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{Mg}}^{2 + }$$\end{document} ions. In this work, stoichiometric ratio for the synthesis process to be taken is Co1-xMgxAl2O4x=0.00,x=0.06\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{Co}}_{{1 - {\text{x}}}} {\text{Mg}}_{{\text{x}}} {\text{Al}}_{2} {\text{O}}_{4} { }\left( {{\text{x}} = 0.00,{\text{ x}} = 0.06} \right)$$\end{document} for the preparation of nanoparticles. The XRD analysis revealed a single-phase mixed spinel ferrite, whereas a scanning electron microscopy (SEM) analysis revealed spherical particles with a size of 20 nm. Williamson–Hall (W–H) method was also used to determine the microstructural parameters of Mg2+-doped cobalt aluminate nanoparticles. Fourier Transform Infrared (FT-IR) spectrometer has been recorded in the wavenumber range of 4000-400cm-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$4000 - 400{\text{ cm}}^{ - 1}$$\end{document} for the presence of various vibrational and stretching bands in the metal aluminates. A band gap energy value of 2.25eV\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$2.25{\text{ eV}}$$\end{document} and 2.74eV\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$2.74{\text{ eV}}$$\end{document} was estimated for undoped and doped cobalt aluminate\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{cobalt aluminate}}$$\end{document} nanoparticles using Tauc plot through UV–visible study. The transmission electron microscopy (TEM) analysis showed the synthesized nanoparticles display a mixed spherical and cubical shaped nanoparticles with good crystallinity in nature. Important magnetic parameters of the metal aluminate nanoparticles are also noted using Vibrating Sample Magnetometer (VSM) which confirmed the ferromagnetic nature of the material and could be good candidates for microwave a biomedical application.